qt-translation-example

• Use menu to switch between German and English.
• Tested on macOS and Android using Qt 5.9.4 LTS

Based on this example:

• https://wiki.qt.io/How_to_create_a_multi_language_application

Working with Qt Translation

• For all displayed and printed string literals in you app use tr().
• The Qt lupdate will serach your project for all tr() and create *.ts files.
  • For example:
    • tr("Hello %1 !").arg(nameFirst)
  • http://doc.qt.io/qt-5/i18n-source-translation.html

1. Add languages you wish to support to your Qt project file (*.pro) and run qmake again

TRANSLATIONS += \
    languages/TranslationExample_en.ts  \
    languages/TranslationExample_de.ts

2. Use Qt lupdate to auto-generate your inital ts files.

   • From Qt Creator menu select:
     • Tools > External > Linguist > Update Translations (lupdate)

3. For each <message> found in each TSL file translate the <source> text and paste into <translation>

   • Manually change translation/@type attribute from "unfinished" to "finished".
   • Or delete translation/@type attribute after translation.
   • When you run lupdate again, it will removed all translation/@type=finished attributes
     • Missing type attribute is same as "finished"
     • Y
   • For small one-by-word projects, use free web browser Google Transalte.
     • https://translate.google.com/?
   • I made this node.js script that requires a commercial Google Trnaslate API key:
     • https://github.com/esutton/i18n-translate-qt-ts

4. Use Qt lrelease to generate compressed *.qm files from translated *.ts files

   • From Qt Creator menu select:
     • Tools > External > Linguist > Release Translations (lrelease)

5. Copy *.qm files to the embedded resource folder ./res/translation

   • ToDo: Add code to *.pro file to copy *.qm to ./res/translation

Automated Translation Using Google Translate

i18n-translate-qt-ts

I created this i18n-translate-qt-ts as a node.js command line utility.

Use requires a commercial Google Translate API key:

• https://github.com/esutton/i18n-translate-qt-ts

To add translations to all ./languages/*.ts files in the qt-translation-example project:

# Use environment variable to store your API key
export API_KEY=AIzy0Vj...AIzy0VjQ
node index.js ${API_KEY} languages en

• If errors occur, you may need to run multiple times until all strings have translations.
  • Perhaps throttling the API calls might help this.
• If needed, send auto-translations to a native speaker for improvements.
  • i18n-translate-qt-ts will not update a manual translation unless translation/@type=unfinished or source string is non-empty and <translation> is empty.